The present invention relates to the field of light projectors.
Automated light projectors are known in the art, and are used in a variety of applications including theatrical productions, television productions, musical performances, and architectural lighting.
In general, these automated light projectors are designed to allow a user to vary one or more lighting parameters from a remote location via lighting control console. These lighting parameters may include, for example, pan, tilt, intensity, beam size, beam shape, and color. For example, U.S. Pat. No. 4,914,556 describes a color mixing system, U.S. Pat. No. 4,855,884 describes a mechanism for varying beam size, and U.S. Pat. No. 4,891,738 describes a mechanism for varying beam shape.
In accordance with a first embodiment of the present invention, a light projector is provided which includes an elliptical reflector, a first spherical retro-reflector and a second spherical retro-reflector. The first retro-reflector has a first aperture formed therein, and the first aperture has a first diameter and a first center-point. The second spherical retro-reflector is located between the elliptical reflector and the first retro-reflector, and the second retro-reflector has a second aperture formed therein, and the second aperture has a second diameter and a second center-point, wherein the second diameter smaller than the first diameter and the first and second center-points lie along a common axis. The light projector also includes a light source located at a foci of the elliptical reflector. The light source (e.g., the arc gap of a gas discharge lamp) lies along the common axis, and the elliptical reflector reflects light emitted by the light source so that the reflected light passes through the first and second apertures. The first and second retro-reflectors are positioned so as to reflect light emitted by the light source back towards the light source. In this manner, light which was not initially directed to the elliptical reflector from the light source is redirected to the light source by the first or second retro-reflectors, passes through the light source to the elliptical reflector, and is reflected back through the first and second apertures.
Preferably, the elliptical reflector, the first retro-reflector, and the second retro-reflector are each comprised of a base portion which is heat conductive, and the base portion has a coating applied thereto which reflects visible light and absorbs infra-red light. The base portion of each of the elliptical reflector, the first retro-reflector, and the second retro-reflector, in turn, is in contact with a heat sink. In this manner heat generated by the light source is dissipated through the heat sink. In certain embodiments, this allows the light projector to operate without any fans. Preferably, the base portion is made of polished, hard anodized aluminum, the coating is a dielectric coating, and the heat sink is constructed as a plurality of heat sink fins. The light projector in accordance with this embodiment may also include other components, including, for example, a color changing apparatus, a beam shaping apparatus, and a yoke for moving the light projector in a panning (e.g. horizontal rotation) or tilting (e.g. vertical rotation) movement.
In accordance with a second embodiment of the present invention, a light projector is provided which includes a light beam source for projecting a beam of light along an axis and a beam shaping apparatus disposed along the axis. The light beam source can be of any construction, including, for example, any conventional light source and reflector arrangement. The beam shaping apparatus includes a first beam shaping wheel and a second beam shaping wheel. The first beam shaping wheel has a first plurality of apertures disposed about its periphery, and at least one of said apertures has a first cylindrical lens disposed therein. The second beam shaping wheel has a second plurality of apertures disposed about its periphery, and at least one of said apertures having a second cylindrical lens disposed therein. The first beam shaping wheel is rotatable to selectively pass each of the first plurality of apertures through the axis and the second beam shaping wheel is rotatable to selectively pass each of the second plurality of apertures through the axis. Preferably, the first and second beam shaping wheels are independently rotatable. In accordance with a further aspect of this embodiment, each of the first and second cylindrical lenses is rotatable within its respective aperture. Preferably, each beam shaping wheel includes at least two cylindrical lenses having different focal lengths. For example, the first beam shaping wheel might include one empty aperture, one aperture with a cylindrical lens with a 100 mm focal length and another aperture with a cylindrical lens with a 150 mm focal length. The second beam shaping wheel could include the same arrangement. Then, by selectively moving lenses from one or both of the first and second beam shaping wheels into the axis, a variety of shapes can be generated. The beam shaping arrangement of the second embodiment may also be used as a beam shaping apparatus for the first embodiment of the present invention described above.
In accordance with a third embodiment of the present invention, an automated lighting fixture is provided which includes a light projector including a light beam source disposed within a housing, a yoke, and a base. The base includes a first motor for rotating the yoke in a horizontal plane. The yoke includes a pair of vertically extending arms coupled to the housing, and the light projector is rotatably secured to the vertically extending arms so that the light projector is movable radially about an axis passing through the vertically extending arms. The yoke also includes a horizontally extending member which joins the vertically extending arms. The horizontally extending member has a length and width which is substantially equal to the length and width of the base. This allows the use of larger bearings for rotating the yoke in the horizontal plane. Preferably, the housing, the base, and the yoke are fabricated from a carbon fiber composite material.
In accordance with another embodiment of the present invention, a light projector includes a light source, a reflector for reflecting light from the light source into a beam of light, the reflector having a base portion which is heat conductive, and having a coating applied thereto which reflects visible light and absorbs infra-red light. A heat sink in contact with the base portion. Preferably, the base portion is made of polished, hard anodized aluminum, the coating is a dielectric coating, and the heat sink is constructed as a plurality of heat sink fins. The reflector can be of any conventional shape depending on the particular application. Examples of suitable reflectors include spherical reflectors, elliptical reflectors, and parabolic reflectors.
In accordance with another embodiment of the present invention, a light projector includes a light beam source for projecting a beam of light along an axis, a strobe wheel disposed between the first retro-reflector and the lens, and a motor coupled to the strobe wheel. The strobe wheel includes a plurality of apertures disposed about its periphery, and is rotatable by the motor so that the plurality of apertures successively pass through the axis. In this manner, a strobe effect can be produced while moving the motor in only one direction, as contrasted with prior art flag-type systems in which the direction of rotation of the motor must be repeatedly reversed.
In accordance with another embodiment of the invention, a wash light is provided which includes a light beam source for projecting a beam of light along an axis and a beam shaping apparatus disposed along the axis. As one of ordinary skill in the art will appreciate, a wash light is a light that is not capable of creating a focused image. In accordance with this embodiment, the light beam source can be of any construction, including, for example, any conventional light source and reflector arrangement. The beam shaping apparatus includes a first beam shaping wheel and a second beam shaping wheel. The first beam shaping wheel has a first plurality of apertures disposed about its periphery, and at least one of said apertures has a first asymmetrical lens disposed therein. The second beam shaping wheel has a second plurality of apertures disposed about its periphery, and at least one of said apertures having a second asymmetrical lens disposed therein. Preferably, the asymmetrical lenses are cylindrical lenses. The first beam shaping wheel is rotatable to selectively pass each of the first plurality of apertures through the axis and the second beam shaping wheel is rotatable to selectively pass each of the second plurality of apertures through the axis. Preferably, the first and second beam shaping wheels are independently rotatable. In accordance with a further aspect of this embodiment, each of the first and second lenses is rotatable within its respective aperture. Preferably, each beam shaping wheel includes at least two cylindrical lenses having different focal lengths. For example, the first beam shaping wheel might include one empty aperture, one aperture with a cylindrical lens with a 100 mm focal length and another aperture with a cylindrical lens with a 150 mm focal length. The second beam shaping wheel could include the same arrangement. Then, by selectively moving lenses from one or both of the first and second beam shaping wheels into the axis, a variety of shapes can be generated. It should be noted that additional beam shaping wheels may also be included in the beam shaping apparatus. The beam shaping arrangement of this embodiment may also be used as a beam shaping apparatus for the first embodiment of the present invention described above.
In accordance with another embodiment of the present invention, a light projector is provided that includes a light source projecting a beam of light and an optical element. The optical element is movable between a first position in which the beam of light does not impinge upon the optical element, a second position in which substantially all of the beam of light impinges upon the optical element, and a plurality of intermediate positions in which a portion of the beam of light impinges upon the optical element, wherein the optical element is comprised of a plurality of radially sectioned sub-elements.
In accordance with another embodiment of the present invention, a light projector is provided that includes a light source projecting a beam of light and a plurality of optical sub-elements. Each optical sub-element is movable between a first position in which the beam of light does not impinge upon the optical sub-element, a second position in which substantially all of the beam of light impinges upon the optical sub-element, and a plurality of intermediate positions in which a portion of the beam of light impinges upon the optical sub-element.
In accordance with another embodiment of the present invention, a light projector is provided that includes a light source projecting a beam of light and a plurality of optical sub-elements, and a base. The base has an opening formed therein and the beam of light is positioned to pass through the opening. Each optical sub-element is movable between a first position in which the beam of light does not impinge upon the optical sub-element, a second position in which substantially all of the beam of light impinges upon the optical sub-element, and a plurality of intermediate positions in which a portion of the beam of light impinges upon the optical sub-element.
In accordance with further aspects of the present invention, methods for operating the embodiments described above are also provided.